function [Ks] = cell2TriMat(KsCell)
nKernel = length(KsCell);
nSmp = size(KsCell{1}, 1);
Ks = zeros(nSmp, nSmp, nKernel);
for i1 = 1:nKernel
    Ks(:,:,i1) = KsCell{i1};
end
end